The Determination of Optoelectronic Properties of Microcrystalline andAmorphous Silicon Films

2001 ◽  
Vol 664 ◽  
Author(s):  
Marinus Kunst ◽  
Susanne von Aichberger ◽  
Wilhelm Thom ◽  
Frank Wünsch
Keyword(s):  
Electronic Properties ◽  
Optoelectronic Properties ◽  
Silicon Films ◽  
Hot Wire ◽  
Laser Crystallization ◽  
Carrier Trapping ◽  
Transient Photoconductivity ◽  
Si Films

ABSTRACTThe study and characterization of the (opto)electronic properties of a-Si:H and µSi filmsby contactless transient photoconductivity measurements is presented. The importance ofminority carrier trapping is shown for the example of a-Si:H films prepared with different dopinglevels. It is shown that the microwave mobility determined by these measurements is a versatiletool for the characterization of the films. Examples are given by the study of µ Si filmsproduced by laser crystallization of a-Si:H films and the optimization of the substratetemperature for the Hot Wire deposition of µ Si films.

scholarly journals Synthesis and Optoelectronic Properties of Iptycene–Naphthazarin Dyes

Synlett ◽  
2018 ◽  
Vol 30 (01) ◽  
pp. 54-58 ◽  
Author(s):  
Timothy Swager ◽  
Cagatay Dengiz ◽  
You-Chi Wu
Keyword(s):  
Single Crystal ◽  
Electronic Properties ◽  
Diels Alder ◽  
Optoelectronic Properties ◽  
Synthesis And Characterization ◽  
Nmr Analysis ◽  
X Ray ◽  
Vis Spectroscopy

We report the synthesis and characterization of iptycene–naphthazarin dyes by using a sequential Diels–Alder approach. The tautomerization of naphthazarin was used as the key step in the synthesis, with structures confirmed by single-crystal X-ray and NMR analysis. The systematic trends in electronic properties were investigated by UV/Vis spectroscopy. BF2 complexes of the dyes were prepared by reaction with BF3·OEt2 in CH2Cl2.

Microstructure Characterization of Amorphous Silicon Films by Effusion Measurements of Implanted Helium

2013 ◽  
Vol 1536 ◽  
pp. 175-180 ◽  
Author(s):  
W. Beyer ◽  
W. Hilgers ◽  
D. Lennartz ◽  
F.C. Maier ◽  
N.H. Nickel ◽  
...  
Keyword(s):  
Thin Film ◽  
Amorphous Silicon ◽  
Low Temperatures ◽  
Plasma Deposition ◽  
Hydrogenated Amorphous Silicon ◽  
Silicon Films ◽  
Hot Wire ◽  
Common Features ◽  
Hydrogenated Amorphous

ABSTRACTAn important property of thin film silicon and related materials is the microstructure which may involve the presence of interconnected and isolated voids. We report on effusion measurements of implanted helium (He) to detect such voids. Several series of hydrogenated and unhydrogenated amorphous silicon films prepared by the methods of plasma deposition, hot wire deposition and vacuum evaporation were investigated. The results show common features like a He effusion peak at low temperatures attributed to He out-diffusion through a compact material or through interconnected voids, and a He effusion peak at high temperatures attributed to He trapped in isolated voids. While undoped plasma-grown device-grade hydrogenated amorphous silicon (a-Si:H) films show a rather low concentration of such isolated voids, its concentration can be rather high in doped a-Si:H, in unhydrogenated evaporated material and others.

Low Defect Density Microcrystalline-Si Deposited by the Hot Wire Technique

1998 ◽  
Vol 507 ◽  
Author(s):  
A. H. Mahan ◽  
M. Vanecek ◽  
A. Poruba ◽  
V. Vorlicek ◽  
R. S. Crandall ◽  
...  
Keyword(s):  
Electronic Properties ◽  
Defect Density ◽  
Structural Data ◽  
Hot Wire ◽  
Very High Frequency ◽  
Deposition Parameters ◽  
Optical And Electronic Properties ◽  
High Filament ◽  
Si Films ◽  
Substrate Temperatures

ABSTRACTThe optical and electronic properties of a series of microcrystalline silicon (μ-Si) films, deposited by the hot wire (HW) technique, are reported. Preliminary results suggest, using moderate H2 /SiH4 dilution ratios and substrate temperatures (320°C), high filament temperatures, and no H gas purifier, that the subgap absorption for these films, measured using the constant photocurrent (CPM) method, can be as low as that obtained for films deposited by the very high frequency glow discharge (VHF-GD) technique. The film dark conductivities of the HW samples, ranging as low as 2.0 × 10−8 (ohm cm)−1, lend further credance to these low defect values. At the same time, the optical absorption in the region > 1.6 eV is higher than that previously observed for the VHF-GD deposited samples. The present results, discussed in the context of the film microcrystalline fraction, suggest that there is no unique, good quality, low defect density μ-Si material, and that different deposition techniques can be used to successfully deposit device quality gc-Si. We also present optical and structural data for films deposited at lower substrate temperatures and higher deposition rates, and suggest combinations of deposition parameters to be used that may further improve the electronic properties of these films.

Defects Characterization of Arsenic Implanted Silicon by Ac Hall Effect Measurements

1986 ◽  
Vol 71 ◽  
Author(s):  
H. Jaouen ◽  
G. Ghibaudo ◽  
C. Christofides
Keyword(s):  
Hall Effect ◽  
Long Range ◽  
Silicon Films ◽  
Experimental Results ◽  
Isochronal Annealing ◽  
Transport Models ◽  
Hall Effects ◽  
Hall Effect Measurements

AbstractAC and DC Hall effects measurements as a function of temperature (77-300K) and frequency ( 1Hz-100KHz) have been performed to characterize Implanted Silicon films. This technique enables the determination of the annihilation processes of defects In such layers as a function of temperature of isochronal anneallngs (300°C to 1100°C during 1 hour). The experimental results are discussed with respect to proper transport models based on short and long range disorder considerations in order to find out the features of defects and Inhomogeneities arising from implantation and their thermal annihilation after isochronal annealing.

Hot-wire chemical vapor deposition and characterization of p-type nanocrystalline Si films for thin film photovoltaic applications

2012 ◽  
Vol 520 (16) ◽  
pp. 5200-5205 ◽  
Author(s):  
Hsin-Yuan Mao ◽  
Shih-Yung Lo ◽  
Dong-Sing Wuu ◽  
Bing-Rui Wu ◽  
Sin-Liang Ou ◽  
...  
Keyword(s):  
Thin Film ◽  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Hot Wire ◽  
Photovoltaic Applications ◽  
Si Films ◽  
P Type ◽  
Nanocrystalline Si

Photoconductive Polycrystalline Silicon Films on Glass Obtained by Hot-Wire CVD

1996 ◽  
Vol 420 ◽  
Author(s):  
A. R. Middya ◽  
J. Guillet ◽  
J. Perrin ◽  
J. E. Bouree
Keyword(s):  
Polycrystalline Silicon ◽  
Chemical Vapour ◽  
Columnar Structure ◽  
Silicon Films ◽  
High Deposition Rate ◽  
Hot Wire ◽  
Si Films ◽  
Polycrystalline Silicon Films ◽  
Deposited Films

AbstractTextured polycrystalline silicon films with columnar structure have been deposited on glass at low temperature (400–550°C) and high deposition rate (10 to 15 Å/s) by hot-wire chemical vapour deposition using SiH4-H2 gases. The homogeneity of the deposited layer is ± 5% on a 8 cm diameter. As deposited films have a poor photoconductivity. However hydrogen confinement in the films during the deposition or after the deposition is found to be the key for obtaining g.tc/poly-Si with a significant diffusion length. Eventually reasonable values of the mobility lifetime product (> 10−7 cm2/V) are obtained by in situ hydrogen passivation of poly-Si films after deposition. Efficient shifting of the Fermi level is achieved by in situ B or P doping. The incorporation of boron in poly-Si network strongly influences the morphology and the crystalline structure. Undoped films have a Hall mobility of 14 ± 5 cm2/V.s which decreases versus the carrier concentration.

Understanding Structure and Electronic Properties of Extended Self-Interstitial Defects in Silicon

1998 ◽  
Vol 538 ◽  
Author(s):  
P. Alippi ◽  
L. Colombo
Keyword(s):  
Electronic Properties ◽  
Tight Binding ◽  
Structural Features ◽  
Dynamics Simulation ◽  
Formation Mechanisms ◽  
Equilibrium Configurations ◽  
Formation Energies ◽  
Atomic Stress

AbstractThe results of an atomistic investigation on the coalescence mechanisms of self-interstitial {311} defects are presented. Formation energies and equilibrium configurations of defect structures are determined by tight-binding molecular dynamics simulation. We focus on the characterization of the lattice strain field around the defect complex: By means of the determination of the atomic stress distribution, we discuss how it may influence the formation mechanisms of the planar {311} structures. We also attempt a correlation between structural features and electronic properties through the analysis of defect-related orbitals occupations and inverse participation ratios.

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